Visara the Dreadful is strictly better six times over, except that this kills indestructibles and occasionally pumps an unblocked attacker.

I like to imagine that this and Visara represent the worst and best possible results of a series of coin flips, and that there are 62 other intermediate forms out there somewhere...
❏ Cost 1 less
❏ Flying
❏ +1/+0
❏ +0/+1
❏ No upkeep cost
❏ Tap for Terminate instead of +3/-2